The invention relates generally to exit devices and deals more particularly with an exit device which is manually operable from the inside by a pushbar or electrically controllable by a low power dogging assembly for holding down the pushbar, and an electromechanical actuator for operating a latch bolt.
Although the dogging and actuating components of the present invention have wide usage, they may be combined with an exit device disclosed in U.S. Pat. No. 3,877,262. The patented exit device is operable from the inside of a door by manual depression of a pushbar which is coupled to a latch bolt, by a push button on the inside of the door or by a doorknob on the outside of the door. A manually operated dogging mechanism is provided to hold down the pushbar. The patented dogging mechanism is spring biased to an outward position and includes a housing mounted to the pushbar which housing provides a journal for a rotary part disposed with its axis normal to the longitudinal axis of the pushbar. The rotary part has an eccentric cam, and a hexagonal slot adapted to receive a hexagonal key used to turn the rotary part. Rotation of the rotary part in a clockwise direction from its undogged position brings the cam into engagement with an abutment surface of a keeper which is mounted to a frame. The frame is fixedly mounted to the door. The keeper includes an inner aperture, and depression of the pushbar drives the rotary part inwardly and the cam into alignment with the keeper aperture. Further rotation of the cam causes it to enter the aperture and thereby prevent the pushbar from returning to its outward position under the influence of the springs.
Such a dogging mechanism is useful during heavy access times such as at the start and end of a work shift and during emergencies to facilitate entry and exit through the door and to lessen the wear on the movable parts associated with the pushbar and latch.
Another previously known exit device of this general type is operable from the inside of the door by manual depression of a pushbar coupled to a door latch or by retraction of the pushbar directly by a solenoid. The solenoid may also be used to dog the pushbar in its retracted position during heavy usage or emergencies. The pushbar has a substantial mass and is spring biased to its outward position so that the solenoid must provide a substantial force to retract the pushbar. Consequently, the solenoid requires substantial electrical power to operate which power must be supplied to the movable door. Because of the magnitude of the power required, convenient hinge connectors cannot be utilized to supply the power to the solenoid, and instead, an undesirable external cable is required. In addition, the solenoid dissipates substantial energy into the exit device.
Accordingly, a general object of the present invention is to provide a low power, electrically operated exit device.
Another general object of the present invention is to provide an electrically actuated dogging assembly for an exit device having a pushbar which dogging assembly requires less power to operate than the aforesaid previously known electric dogging device.
Another general object of the present invention is to provide a dogging assembly of the foregoing type which is adaptable to exit devices having operating mechanisms other than pushbars.
Still another general object of the present invention is to provide an electromechanical actuator which is adaptable to an exit device of the type disclosed in the U.S. Pat. No. 3,877,262 as well as other type of exit devices.
A more specific object of the present invention is to provide a dogging assembly and an electromechanical actuator of the foregoing types which are compatible with one another for installation in a single exit device.